How to make a global leaderboard?

So on the Dev Forum there was a tutorial to make a global leaderboard, yet when I entered the code nothing worked? I published the game and went to it and it said that message saying "Game may not function as intended. Developer needs to update the game." So I am wondering if maybe Roblox updated their scripting system (considering the tutorial was made a year ago) and if they did what would the new code be? I know how to work the GUIs so all I need to know is the scripting part. Here is the tutorial I used so you can see if the code is outdated: https://devforum.roblox.com/t/how-to-make-a-simple-global-leaderboard/256754/5